Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!feeder.erje.net!us.feeder.erje.net!news2.arglkargh.de!news.swapon.de!eternal-september.org!feeder.eternal-september.org!mx02.eternal-september.org!.POSTED!not-for-mail
From: Matthew Carter <m@ahungry.com>
Newsgroups: comp.lang.php
Subject: Re: OO PHP result of new if a constructor fails
Date: Wed, 12 Nov 2014 01:30:53 -0500
Organization: Ahungry (http://ahungry.com)
Lines: 66
Message-ID: <87wq71ue02.fsf@ahungry.com>
References: <m3t91i$rp6$1@dont-email.me> <4146385.JyWBYEY6r6@PointedEars.de> <m3uevr$s4b$1@solani.org> <871tp9w15b.fsf@ahungry.com> <m3ukj6$5e8$1@dont-email.me>
Mime-Version: 1.0
Content-Type: text/plain
Injection-Info: mx02.eternal-september.org; posting-host="7c986cd4736462de309a749b207746fe"; logging-data="29959"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX1/u5WDnUPXTHrmTOes4i5p/"
User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.4 (gnu/linux)
Cancel-Lock: sha1:tsmLF04rLqBx8ss/s2gIYI9oVcQ= sha1:7a7E1wJw69M7HF65FInXD12AlQc=
Xref: csiph.com comp.lang.php:14544

Jerry Stuckle <jstucklex@attglobal.net> writes:

> On 11/11/2014 10:25 PM, Matthew Carter wrote:
>> "Christoph M. Becker" <cmbecker69@arcor.de> writes:
>> 
>>> Thomas 'PointedEars' Lahn wrote:
>>>
>>>> James Harris wrote:
>>>>
>>>>> I understand that PHP constructors cannot return anything
>>>>
>>>> Doubtful.
>>>
>>> AIUI, a PHP constructor is the method __construct, and that does not
>>> create an object, but merely initializes it, so the constructor can be
>>> thought of as a command (opposed to a query), and as such would never
>>> return anything (at least when properly called within a /new/ statement).
>> 
>> Although you can return any value you like when an extending class calls
>> it via a parent::__construct() call.
>> 
>
> Although PHP may not complain (I don't know, I've never tried it),
> returning a value from a __construct() method is documented as invalid.
>  See http://php.net/manual/en/language.oop5.decon.php.  The return value
> of the function is void (no return value).

So would this be a case of a bug in PHP or a bug in the documentation?

<?php

class foo
{
  public function __construct ()
  {
    return 42;
  }
}

class bar extends foo
{
  public function __construct ()
  {
    $z = parent::__construct ();
    var_dump ($z);
  }
}

$a = new bar ();
$b = new foo ();
var_dump ($b->__construct ());

Produces output (with all warnings turned on):
int(42)
int(42)

Obviously magically calling/running the __construct via a new class
instance disregards the return result though.





-- 
Matthew Carter (m@ahungry.com)
http://ahungry.com